The most common causes of posterior uterus are the following: First, congenital physiological posterior uterus, some women are born with a posteriorly inclined and posteriorly flexed uterus, which clinically does not affect normal menstruation and normal sex life, and can lead to normal pregnancy and delivery without special treatment. Secondly, the posterior position of the uterus caused by surgery, such as the adhesion of the uterus after caesarean section, causes the posterior position of the uterus or due to the surgery of uterine fibroids or ectopic pregnancy, causes the change of the position of the uterus. Clinically, posterior uterus caused by surgery does not require special treatment if there are no corresponding clinical symptoms. Thirdly, patients with pelvic endometriosis may cause posterior uterus. Due to pelvic endometriosis, pelvic adhesions and uterine enlargement, posterior uterus may be accompanied by lumbago, abdominal distension, anal drop or dysmenorrhea. If it affects normal life it should be treated accordingly to avoid aggravation of the condition.